iPhone 13 pro max iPhone 13 Pro Max battery at 87% after one year, battery 87% peak performance, just one year old

Well, mine own i13PM, acquired last Nov. 22, is showing 98% max after these two months, your 13% drop after 12 would seem to be in line. Given my i8+ got a free battery at close to the end of its AppleCare+ coverage and thus lasted for 5+ years, I was sure to get AC+ too for the i13PM.

Hello dman75,

Thank you for reaching out to Apple Support Communities.

This may be helpful:

How to maximize battery performance

“Battery life” is the amount of time a device runs before it needs to be recharged. “Battery lifespan” is the amount of time a battery lasts until it needs to be replaced. One factor affecting battery life and lifespan is the mix of things you do with your device. No matter how you use your device, there are ways to help. A battery’s lifespan is related to its “chemical age,” which is more than just the passage of time. It includes different factors, such as the number of charge cycles and how it was cared for. Follow these tips to maximize battery performance and help extend battery lifespan. For example, keep iPhone half-charged when it’s stored for the long term. Also avoid charging or leaving iPhone in hot environments, including direct sun exposure, for extended periods of time.

As outlined here: iPhone Battery and Performance

For more details on how to maximize your battery lifespan, we would recommend reviewing: Maximizing Battery Life and Lifespan

Hopefully this helps.

Cheers!